Question how to add time duration for ffmpeg record/play

[jimdagys]

I have ffmpeg ver 3.1.4 using on Windows 7 32 bit with vlc ver 2.2.4.
I use this command to simultaneously record and play an internet radio station and this works fine.

ffmpeg -i "https://ais-sa1.streamon.fm/7648_48k.aac" ^
    -c copy output.aac ^
    -f wav -acodec pcm_s16le -ac 2 - | "C:\Program Files\videolan\vlc\vlc.exe" -

I can manually stop ffmpeg record/play by either closing vlc or closing ffmpeg and this leaves me with a completed audio file.

However, I want to add something to limit the record/play to a certain time, for example 30 seconds, after which ffmpeg will stop recording/playing the radio station (stop using data) and leave me with a completed audio file. I tried adding this to the code:

-t 00:00:30

in various ways but was unsuccessful. In actual practice, I would like to stop the record/play about 4 hours 30 minutes.
Could someone give me the exact working code (using above example radio station) that will record/play for specific time and then stop recording/playing and stop using data.
Thank you.

[jagabo]

The duration needs to have seconds as a float, not an integer.

-t 00:00:30.0

I believe it has to be after the input spec too.

It looks like your batch file needs the time limit twice:

ffmpeg -i "https://ais-sa1.streamon.fm/7648_48k.aac" ^
    -t 00:00:10.0 ^
    -c copy output.aac ^
    -t 00:00:10.0 ^
    -f wav -acodec pcm_s16le -ac 2 - | "G:\program files\videolan\vlc\vlc.exe" -

Once for the aac output, again for the wav output to VLC.

[jimdagys]

Ok, this seems to work (ffmpeg records/plays for 30 seconds).

ffmpeg -i "https://ais-sa1.streamon.fm/7648_48k.aac" ^
    -t 00:00:30.0 ^
    -c copy output.aac ^
    -t 00:00:30.0 ^
    -f wav -acodec pcm_s16le -ac 2 - | "C:\program files\videolan\vlc

Thank you.
I do have a question. In the command output, what does the "more' mean (shown four times with red mark)? Also, why do I have to press enter to continue at that point (shown with green mark)?

[jagabo]

The CLI just telling you it's ready for more input since the previous line ended with a ^. I ran it from a batch file so all the lines were simply concatenated before being executed:

ffmpeg -i "https://ais-sa1.streamon.fm/7648_48k.aac"     -t 00:00:10.0     -c copy output.aac     -t 00:00:10.0     -f wav -acodec pcm_s16le -ac 2 -   | "G:\program files\videolan\vlc\vlc.exe" -